The genesis of machine addressing probably is shown in the U.S. Pat. 558,936 issued Apr. 28, 1896 to Joseph S. Duncan, one of the founders of the business later to become the Addressograph Multigraph Corporation. Slow as it was, it provided accurate addressing from fixed plates.
From such start, a sophisticated line of business machines, such for example as the one shown in U.S. Pat. No. 2,359,850, were developed to do repetition printing of addresses and other fixed information from metal plates stored in a long storage drawer. These machines are designed for long hard service conditions of large mailing demands.
The present invention provides an improved system for controlling the operation of plate and sheet feed assemblies in a printing apparatus. The control system includes a detector arrangement which detects the removal of a printed sheet of material from the printing station and the arrival of a succeeding sheet of material at the printing station. A second detector arrangement detects the removal of one printing plate from the printing station and the arrival of a succeeding printing plate at the printing station. The control system will interrupt operation of the printing apparatus in response to a failure of a previously printed sheet of material to be removed from the printing station or a failure of a succeeding sheet of material to arrive at the printing station. In addition, the control system will interrupt operation of the printing apparatus in response to a failure of one of the printing plates to be removed from the printing station or a failure of a succeeding printing plate to arrive at the printing station.
Accordingly, it is an object of this invention to provide a new and improved printing apparatus having a control system for controlling the operation of sheet and plate feed assemblies wherein the control system is operable to interrupt operation of the printing apparatus in response to improper feeding of either a sheet of material or a printing plate.
Another object of this invention is to provide a new and improved apparatus for printing on each one of a plurality of sheets of material in turn at a printing station with a plurality of printing plates and wherein the apparatus includes a sensor which detects initial movement of the leading end portion of a first sheet of material from a printing station under the influence of a sheet feed assembly and a control system which will initiate movement of a succeeding sheet of material toward the printing station in response to detection of movement of the leading end portion of the first sheet material from the printing station.
Another object of this invention is to provide a new and improved apparatus for printing on each one of a plurality of sheets of material in turn at a printing station with printing plates and wherein the apparatus includes a reciprocatable plate feed device which is movable from an extended position in which it extends into a plate holder to a retracted position in which the plate feed device is spaced from the plate holder to thereby effect movement of a printing plate toward a printing station and a control system which is operable to interrupt operation of the printing apparatus with the plate feed device in the retracted position in response to an improper feeding of either a printing plate or a sheet of material.